<!doctype html>
<meta charset=utf-8>
<title>Selection with nested videos doesn't crash</title>
<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1887963">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script>
async_test(t => {
  document.addEventListener("DOMContentLoaded", () => {
    let c = a.attachShadow({mode: "open"});
    const sel = window.getSelection();

    sel.setBaseAndExtent(b, 0, c, 0);

    assert_equals(sel.anchorNode, b);
    assert_equals(sel.anchorOffset, 0);
    assert_equals(sel.focusNode, b);
    assert_equals(sel.focusOffset, 0);
    t.done();
  })
}, 'selection have the same anchor and focus nodes because b and c are in different tree scopes.');

</script>
<div id="a">A</div>
<video>
  <video id="b"></video>
</video>
